Overview

Choroideremia is a genetic disorder that causes blindness in men. It affects approximately one in 50,000 people. The condition is caused by a fault in the gene known as CHM. There are no treatments for choroideremia yet but the team is carrying out a clinical trial of gene therapy.

The CHM gene makes a protein called REP-1. It’s in every cell in the body and is a key player in how cells work, helping some of the machinery inside the cells get to the right place. When REP-1 is missing from the light-sensitive layer of the eye (the retina), this doesn’t happen. It gradually kills the retinal cells but we don’t yet understand exactly how. We also don’t know why this happens at very different rates from person to person. The team wants to find out.

They are recruiting 9 patients at 3 different stages of the condition to take a skin sample from each. The skin cells are very easy to grow in the lab, so the team can create a ‘disorder in a dish’. They are measuring what’s inside the cells at the different stages of choroideremia’s progress to see whether any differences can be linked to the stage.

The aim is to predict the rate at which each individual’s sight loss is likely to progress. This will be useful for people with choroideremia themselves and also for planning future clinical trials, for example to understand how an individual responds to gene therapy.